Greebster, I would agree, But...
Bernts' Kitahari as pictured and described is similar to the current offering as made by Precide...
Oskar Heil A.M.T.
...will have a 'figure 8' polar pattern similar to my ESS AMT 1 drivers, but 'tilted' to one side or the other (if made in a 'left/right' configuration, lens left or right), which is what makes sense to me. From what I gather from the Precide site, the 'lens' that you refer to is 'flipped' on the front vs. the back (front, left...rear, right. Flip for the opposite channel...), which ought to create a pair that you'd have to mark in some fashion.
Hey, I waiting to see what what happens to what he's doing too. *L* I'd love to see a line source stack of amts' linked to some woofers and subs to handle the bass... It'd be astounding IMHO.
Obviously, it'll take a bit of work to get there, But....it beats tv.... *L*
Bernts' Kitahari as pictured and described is similar to the current offering as made by Precide...
Oskar Heil A.M.T.
...will have a 'figure 8' polar pattern similar to my ESS AMT 1 drivers, but 'tilted' to one side or the other (if made in a 'left/right' configuration, lens left or right), which is what makes sense to me. From what I gather from the Precide site, the 'lens' that you refer to is 'flipped' on the front vs. the back (front, left...rear, right. Flip for the opposite channel...), which ought to create a pair that you'd have to mark in some fashion.
Hey, I waiting to see what what happens to what he's doing too. *L* I'd love to see a line source stack of amts' linked to some woofers and subs to handle the bass... It'd be astounding IMHO.
Obviously, it'll take a bit of work to get there, But....it beats tv.... *L*
...but I'm involved in making Walsh drivers out of trash...obviously not to be taken seriously...*smirk*
The ESS drivers have a 'lens' similar, but on both sides of the exposed pleats in the center. If an acoustic lens exists, it's being created on both sides, equally. If the lens exists to create the necessary magnetic 'environment' (if you will) for the metal in the folds of the pleated ribbon to function properly... Oh, well. Such 'adjustments' are made for the typical speaker variety to make it function in a relatively acceptable fashion...'relative', of course, being 'subjective'....*S*
The ESS drivers have a 'lens' similar, but on both sides of the exposed pleats in the center. If an acoustic lens exists, it's being created on both sides, equally. If the lens exists to create the necessary magnetic 'environment' (if you will) for the metal in the folds of the pleated ribbon to function properly... Oh, well. Such 'adjustments' are made for the typical speaker variety to make it function in a relatively acceptable fashion...'relative', of course, being 'subjective'....*S*
I have measured 4 amt´s. All measured in same conditions .1 meter distance, 2,9volt, on axis.
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ESS 1
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ESS 2
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6,5mmx40x80mm 2 pc.
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8mm 40x80mm 2pc. New diaphragm´s
I could not place the new diaphragms in the "kithara" magnetsystem.too thick 8mm in a 10mm "gap"
The Kithari system is made from 3x15mm iron.I think it behaves like the standard ESS speaker.Dispersion is limited in horisontal direktion
Bernt
ESS 1
ESS 2
6,5mmx40x80mm 2 pc.
8mm 40x80mm 2pc. New diaphragm´s
I could not place the new diaphragms in the "kithara" magnetsystem.too thick 8mm in a 10mm "gap"
The Kithari system is made from 3x15mm iron.I think it behaves like the standard ESS speaker.Dispersion is limited in horisontal direktion
Bernt
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So if the pleats are 6,5 and 8 mm deep, how wide are they?
Would you say that the different cutoff frequencies are due the quarter wavelength, that is the pleats act as HH-resonators?
To remember is that 6,5 and 8 mm are ideal measurements, in reality the pleats are more likely to be less deep. For instance would a 6,5 mm deep pleat be 5,5 in reality giving a HH-resonator at 15,5 kHz and 8 mm would be 7 mm giving a HH-resonator at 12,3 kHz.
Would you say that the different cutoff frequencies are due the quarter wavelength, that is the pleats act as HH-resonators?
To remember is that 6,5 and 8 mm are ideal measurements, in reality the pleats are more likely to be less deep. For instance would a 6,5 mm deep pleat be 5,5 in reality giving a HH-resonator at 15,5 kHz and 8 mm would be 7 mm giving a HH-resonator at 12,3 kHz.
Hi båndsei
Very interesting, both to see the freq response but als the dist figures.
No 3 has by far teh best dist figures, and also very good low end.
But why is ther a clear resonance at around 450 Hz .... all are OB measurements ... right?
Also the distortin raise from 5 kHz in all measurements ... is theis due to some limitations in the measurement setup/sw?
Could you post pictures of the 4 AMTs? ......
Really interesting to see the differences her. Super cool.
Thanks
Baldin
Very interesting, both to see the freq response but als the dist figures.
No 3 has by far teh best dist figures, and also very good low end.
But why is ther a clear resonance at around 450 Hz .... all are OB measurements ... right?
Also the distortin raise from 5 kHz in all measurements ... is theis due to some limitations in the measurement setup/sw?
Could you post pictures of the 4 AMTs? ......
Really interesting to see the differences her. Super cool.
Thanks
Baldin
Jerryrigged
I meant vertical,and i agree about the horisontal.I use 2 amts angeled 10' to get better vertical dispersion.
I will comment on my Measurements later.
I made the Kithara magnetsystem to get higher efficiency,a stronger field ,and better control of the diaphragm .It seems it´s not nesesary to get good results.
I wont use it I think now.Might make small baffels.
Bernt
I meant vertical,and i agree about the horisontal.I use 2 amts angeled 10' to get better vertical dispersion.
I will comment on my Measurements later.
I made the Kithara magnetsystem to get higher efficiency,a stronger field ,and better control of the diaphragm .It seems it´s not nesesary to get good results.
I wont use it I think now.Might make small baffels.
Bernt
Baldin
I have listened to all 4 without filter, fullrange ,and it is very easy to hear the differenses .The latest, with 8mm pleats,is very good in low end ,and i cant hear the loss in the high end.I think few can.
I will post Pictures.
They are all "naked".
I don't see a clear resonance.Witch model?
I see the raise in all my Measurements of AMT's.Have to try with cone or dome speakers.
Bernt
I have listened to all 4 without filter, fullrange ,and it is very easy to hear the differenses .The latest, with 8mm pleats,is very good in low end ,and i cant hear the loss in the high end.I think few can.
I will post Pictures.
They are all "naked".
I don't see a clear resonance.Witch model?
I see the raise in all my Measurements of AMT's.Have to try with cone or dome speakers.
Bernt
Resonance at 450 ... could be something rattling .... but it also looks a bit like the low end response of a underdamped closed box behaviour (Qt less than 0.7) ..... but as they are naked .... then that is not the case ... so it must be the nature of low end dipole response, being the relations between the baffle size and the actual driver size .... guess that the magnetstructure is wider than for the others ..... does not matter much if you crossover a lot higher than 450 Hz ....
Electro-acoustic models model A3 .....
Electro-acoustic models model A3 .....
Attachments
I concur with Balwin...if you roll off to your bass driver higher, the 450 gets buried. *G*
Baffles...hmm. Possibly...I'd play with something flexible that's easy to change its' shape, but what doesn't come to mind right now. (Thinking more about dinner right now...stomach is knocking on the rib cage, trying to get my attention, and it's succeeding *L*)
I've toyed with the idea of a baffle that could be placed behind my Heils' to vary it's back reflections to adjust for the room they find themselves in. It'd certainly effect the measurements...how exactly is a big guess ultimately.
Baffles...hmm. Possibly...I'd play with something flexible that's easy to change its' shape, but what doesn't come to mind right now. (Thinking more about dinner right now...stomach is knocking on the rib cage, trying to get my attention, and it's succeeding *L*)
I've toyed with the idea of a baffle that could be placed behind my Heils' to vary it's back reflections to adjust for the room they find themselves in. It'd certainly effect the measurements...how exactly is a big guess ultimately.
Oh, that's got 'cool' smeared all over it, a 'line source AMT'! *BG*
And the 'basic black' support structure gives it a slightly 'menacing' edge. "Don't touch me or I'll vaporize your hand with sound waves....Grrr...." *L*
Seriously....looks great. Measurements when you catch your breath and stop listening.
And the 'basic black' support structure gives it a slightly 'menacing' edge. "Don't touch me or I'll vaporize your hand with sound waves....Grrr...." *L*
Seriously....looks great. Measurements when you catch your breath and stop listening.
Here's more Measurements and a Picture showing units measured.
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Units tested and diaphragms
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Walsh clone
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4" fullrange
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Ess 140x40x4mm.
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2 pcs 80x40x6,5mm.
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3 pcs 80x40x8,5mm.Without "baffel"
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3 pcs 80x40x8,5mm. with "baffel"
Resonancefreq. seems to be app. 250hz.
All Measurements at 1 m. 2.8v on axis.
Bernt
Units tested and diaphragms
Walsh clone
4" fullrange
Ess 140x40x4mm.
2 pcs 80x40x6,5mm.
3 pcs 80x40x8,5mm.Without "baffel"
3 pcs 80x40x8,5mm. with "baffel"
Resonancefreq. seems to be app. 250hz.
All Measurements at 1 m. 2.8v on axis.
Bernt
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